The present invention generally relates to the field of apparatus for clearing a land. More particularly, it concerns a land clearing tractor for selectively clearing a land of brush and trees and a process for clearing a land of brush and trees.
A known procedure which is sometimes called xe2x80x9cpre-commercial clearingxe2x80x9d consists of selectively clearing a land having brush and young trees in order to keep only certain types of trees, and removing the rest of the undesired brush and trees.
Selective clearing is a silvicultural process, which is generally done manually by workers equipped with portative brush clearing machines. The work involves selecting the stems of trees that are to be kept according to predetermined quantity and quality standards, and then cutting the rest of the brush with the portative brush clearing machines as workers walk on the field. As it can be appreciated, such a manual clearing technique can take an enormous amount of time and a large number of workers, especially if the surface to be cleared is large.
There is therefore a need to provide an apparatus and/or a process for improving such selective clearing.
U.S. Pat. No. 4,355,670 (OHRBERG et al.) discloses a vehicle having a clearing head located at the front of the vehicle for fragmenting woody material. The hydraulically adjustable clearing head includes a horizontally disposed cylindrical drum.
U.S. Pat. No. 4,236,554 (NICHOLSON) discloses a tractor having a front feller and chipper. The feller includes an elongated bladed rotary felling cutterhead having its length extending transversely of the tractor between lower front portions. The chipper includes a chipping cutterhead spaced upwards and rearward from the feller.
U.S. Pat. No. 4,232,719 (PAYTON); U.S. Pat. No. 3,754,603 (BOGIE); U.S. Pat. No. 4,390,134 (PAULVE); U.S. Pat. No. 4,537,362 (ZULOAGA); and U.S. Pat. No. 5,526,637 (LEONARD) disclose different systems for clearing brush.
The above-mentioned patents do not provide efficient means to perform selective clearing of brush and trees.
It is an object of the present invention to provide a silvicultural apparatus and a process that satisfies the above-mentioned need. According to a preferred embodiment of the present invention, there is provided a mobile silvicultural apparatus for use in a land of trees, the apparatus comprising:
a steerable wheeled support frame comprising a horizontally extending ground clearing section, and first and second opposite vertical side sections, the ground clearing and side sections defining a tunnel shaped passage through which trees of a certain type are allowed to pass as the support frame travels thereover;
manipulating means mounted to the support frame for selectively manipulating trees of a land;
motor means for imparting motion to the support frame; and control means for controlling the steerable support frame, the motor means, and the manipulating means.
In an alternative preferred embodiment the mobile silvicultural apparatus is a land clearing tractor for selectively clearing a land of brush and trees. There is therefore provided a land clearing tractor for selectively clearing a land of brush and trees, the tractor comprising:
a traction unit for moving the tractor along a direction of travel;
a supporting frame connected to the traction unit, the frame having first and second sides, and a raised section between the first and second sides;
a first shredder head operatively connected to the first side of the frame and oriented parallel to the direction of travel, the first shredder head being movable between elevated and lowered positions for clearing brush and trees in a first band; and
a second shredder head operatively connected to the second side of the frame, the second shredder head being parallel to the first shredder head and spaced apart therefrom, the second shredder head being movable between elevated and lowered positions for clearing brush and trees in a second band spaced apart from the first band and thereby leaving between the first and second bands a residual band of brush and trees.
As can be appreciated, the land clearing tractor according to the present invention cuts brush and trees in a pair of spaced apart bands so that brush and trees between the cut bands can be later selectively cut.
According to another aspect of the present invention, there is provided a land clearing tractor for selectively clearing a land of brush and trees, the tractor comprising:
a traction unit for moving the tractor along a direction of travel;
a frame having an inverted U-shaped cross-section with first and second sides, and a raised section between the first and second sides positioned between 0.5 and 1.5 meters from ground;
a first shredder head operatively connected to the first side of the frame through a first actuating lever arm, the first shredder head being oriented parallel to the direction of travel and being movable between elevated and lowered positions for clearing brush and trees in a first band; and
a second shredder head operatively connected to the second side of the frame through a second actuating lever arm, the second shredder head being parallel to the first shredder head and spaced apart therefrom, the second shredder head being movable between elevated and lowered positions for clearing brush and trees in a second band spaced apart from the first band and thereby leaving between the first and second bands a residual band of brush and trees.
According to yet another aspect of the present invention, there is provided a process for selectively clearing brush and trees of a land, comprising the steps of:
clearing simultaneously first and second parallel and spaced apart bands of brush and trees with a land clearing tractor; and
manually and selectively cutting brush and trees in a residual band between the two parallel and spaced apart bands.
The invention as well as its numerous advantages will be better understood by the following non-restrictive description of a preferred embodiment made in reference to the appending drawings.